plugin-core/docs/src/docs/controllerMethods.adoc

////
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
////

[[controllerMethods]]
== Controller Methods

The plugin registers some convenience methods into all controllers in your application. As of version 3.1.0 this is implemented by a trait that is applied to all controllers but was implemented in earlier versions by adding methods to each controller's `MetaClass`. All are accessor methods, so they can be called as methods or properties. They include:

=== isLoggedIn

Returns `true` if there is an authenticated user.

[source,groovy]
.Listing {counter:listing}. Example use of `isLoggedIn()`
----
class MyController {

   def someAction() {
      if (isLoggedIn()) {
         ...
      }

      ...

      if (!isLoggedIn()) {
         ...
      }

      // or

      if (loggedIn) {
         ...
      }

      if (!loggedIn) {
         ...
      }
   }
}
----

=== getPrincipal

Retrieves the current authenticated user's Principal (a `GrailsUser` instance unless you've customized this) or `null` if not authenticated.

[source,groovy]
.Listing {counter:listing}. Example use of `getPrincipal()`
----
class MyController {

   def someAction() {
      if (isLoggedIn()) {
         String username = getPrincipal().username
         ...
      }

      // or

      if (isLoggedIn()) {
         String username = principal.username
         ...
      }
   }
}
----

=== getAuthenticatedUser

Loads the user domain class instance from the database that corresponds to the currently authenticated user, or `null` if not authenticated. This is the equivalent of adding a dependency injection for `springSecurityService` and calling `PersonDomainClassName.get(springSecurityService.principal.id)` (the typical way that this is often done).

[source,groovy]
.Listing {counter:listing}. Example use of `getAuthenticatedUser()`
----
class MyController {

   def someAction() {
      if (isLoggedIn()) {
         String email = getAuthenticatedUser().email
         ...
      }

      // or

      if (isLoggedIn()) {
         String email = authenticatedUser.email
         ...
      }
   }
}
----